With a few exceptions, the Third Imperium does not rule worlds. Instead, the Imperium claims as its domain the space between the stars. On the face of it, this claim seems meaningless or even silly – space is, after all, rather empty. But empty or not, space is valuable. Every cargo, every message, every diplomatic envoy travels through the space that is the domain of the Third Imperium. Thus the economic and political affairs of each and every member world can be dominated by the fleets of the Third Imperium. The Imperium not only undertakes to rule the vast reaches of space but also to defend them, and thereby the worlds that lie within Imperial territory. The Imperial rule of space is thus not a stranglehold upon the member worlds but a contract between the Imperial rulers and the member worlds. While the Imperial Navy jealously guards its right to control space, so also does it claim the proud duty of guaranteeing the safety of the trade ships and the planetary populations of the member worlds. Although space is the preserve of the Imperium and its Navy, each world is of course entitled to self-government and defense. This means that there must be some meeting point between Imperial and local jurisdiction. The standard terms of Imperial membership allow for a zone of shared jurisdiction between planetary and Imperial forces. This zone begins 10 diameters out from the world and ends at 100; it is not a consequence that 100 diameters is the minimum safe Jump distance. Under 10 diameters is the sole jurisdiction of the planetary forces, except where Imperial intervention has been requested by the world or imposed by legitimate Imperial authorities, or special areas such as Starports, which are considered to be Imperial territory. The 10-diameter zone is patrolled and defended by whatever COACC (Close Orbit and Airspace Control Command) forces the world can muster. Beyond the 100-diameter limit, Imperial authority is absolute. Local vessels are subject to the same rules and controls as foreign (i.e. out-system) vessels moving through that space. However, there are some special considerations. Worlds with holdings elsewhere in the system are allowed courtesy “transit corridors” to and from their offworld holdings, within which local vessels are considered to be in the “shared responsibility” zone and subject to greatly relaxed restrictions. This courtesy is simply to avoid pointless hassle for local traffic, and is not extended to out-system ships unless they are proceeding between points on the transit corridor. Foreign ships crossing the corridor are in Imperial space, and are the responsibility of the Navy. The second exception concerns the right to enforce customs and to provide for local defense. All Imperial member worlds have “standing permission” to meet incoming vessels beyond the 100 diameter limit if necessary, and to station system defense assets anywhere in the system that is not specifically prohibited by, say, the proximity of an Imperial Fleet installation in the outsystem. Standing Permission can be revoked as part of sanctions against an unruly world. System defense vessels operating in what is very definitely Imperial space might seem to be a breach of the Imperial Rule of Space, but this is not the case. Local defense vessels are not foreign warships intruding into Imperial space but are the forces of an Imperial member world protecting local Imperial space against pirates, smugglers and hostile forces. Thus they have every right to deploy for defensive purposes anywhere in local space (normally defined as their home star system, including the system of a binary partner star). Local forces do not have the stop-and-search rights of naval vessels in their own right – as local forces they have no jurisdiction in Imperial space. However, local forces are by definition part of the Colonial Fleet of the Third Imperium and as such are required to uphold Imperial (not local) laws wherever they may be. This not only grants the right to conduct searches, anti-piracy sweeps and so on, but also the duty to do so. These duties are undertaken not in the name of local government but with the Emperor’s authority. How enthusiastic local forces are about these duties does tend to vary from system to system. Jump-capable local forces are treated exactly like sublight vessels, even if they leave the home system. If they are acting as units of the Colonial Fleet (i.e. under orders from the Subsector admiral), they are treated as regular Navy vessels. They must uphold Imperial Law and observe local jurisdiction as if they were visiting fleet units. Colonial vessels often take part in anti-piracy or patrol operations in conjunction with or instead of Imperial Navy ships. However, when not under Imperial orders, the deployment of locally-owned warships beyond the home system is a matter for the discretion of the planetary government, subject to permission from the Imperial Authorities. This is discussed later, under Naval Procedures. Thus the Imperium retains the right to absolute rule of space, yet acknowledges and welcomes the contribution of local forces to that rule. The various gray areas in this arrangement allow for a variety of diplomatic incidents, but this is considered a necessary evil in return for a workable system.